\Header{grid.yaxis}{Draw a Y-Axis on a Grid Viewport}
\keyword{dplot}{grid.yaxis}
\begin{Description}\relax
This function draws a y-axis.\end{Description}
\begin{Usage}
\begin{verbatim}
grid.yaxis(at = NULL, label = TRUE, main = TRUE, gp  =gpar(),
           draw = TRUE, vp = NULL)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{at}] A numeric vector of y-value locations for the tick marks.
\item[\code{label}] A logical value indicating whether to draw the labels
on the tick marks.
\item[\code{main}] A logical value indicating whether to draw the axis
at the left (\code{TRUE}) or at the right (\code{FALSE}) of the
viewport.
\item[\code{gp}] An object of class \code{gpar}, typically the output
from a call to the function \code{gpar}.  This is basically
a list of graphical parameter settings.
\item[\code{draw}] A logical value indicating whether graphics output
should be produced.
\item[\code{vp}] A Grid viewport obect (or \code{NULL}).
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
The \code{"grob"} object contains an object of class \code{"yaxis"}.\end{Details}
\begin{Value}
An object of class \code{"grob"}.\end{Value}
\begin{Author}\relax
Paul Murrell\end{Author}
\begin{SeeAlso}\relax
\link{Grid},
\code{\Link{viewport}},
\code{\Link{grid.xaxis}}\end{SeeAlso}

